Electronic marking device



Nov. 20, 1962 P. BURSTOW ETAL ELECTRONIC MARKING DEVICE 2 Sheets-Sheet 1 Filed July 18, 1958 FIG] mm m 4 H Um H V w UM /N VE N TORS PIERRE BURS 70 W MON/N A 7'TOR/VE V 2 Sheets-Sheet 2 F IG. 2

P. BURSTOW ETAL ELECTRONIC MARKING DEVICE Nov; 20, 1962 Filed July 18, 1958 N l/E N TURS P/MRE BURSTOW CM 005 MON/N 5r W TIORNE Y United States Patent Office 3,%5,305 Patented Nov. 20, 1962 ELECTRONIC MARKING DEVICE Pierre Burstow, Paris, and Claude Monin, Vilienness (Seine), France, assignors to Coinpagnie lndnstrielie ties Telephones, Paris, France, a corporation of France Filed .luiy 18, 1958, Ser. No. 749,522.

Claims priority, application France 5, 1957 3 Claims. 131. 179-18) The present invention relates to an electronic marking device applicable notably to telecommunications.

It is known that for stopping a rotary switch comprising wipers exploring a variable number of contacts disposed at regular intervals along an arc of a circle, it is sufficient to mark by means of a given potential the contact at which the switch is to stop. The passage of the wipers over the marked contact closes a circuit, the effect of which is to stop the rotation precisely at the marked level. The marking proper has consisted in designating one of a plurality of contacts in accordance with the digit dialled by the calling subscriber, and the consecutive rotation of the wipers constitutes a desired setting to the digit received, that is to say, a selection. Thus, a plurality of successive settings permits of determining, digit-by-digit, one of a very large number of lines, the marking and selecting of a digit taking place before the following digit is dealt with.

Another form of making and selection is known, which permits of separating the two functions. In this case, the marking does not take place digit-by-digit, but directly at the called subscriber in accordance with the digits dialled by the calling subscriber and received in a device called a register, the selection thereafter taking place. The principle may be as follows: all the lines, for example 100, are assembled in the form of a matrix, each horizontal row corresponding to a ten and each vertical column to a unit. Thus, the coordinates of any line taken in the matrix correspond to a certain ten and a certain unit. This line may be determined as soon as its number has been received by a register. It is therefore possible thereafter to mark, one of a large number of lines and to establish the path between the connecting circuit (to which the calling subscriber is already connected) and the line only if the latter is free. In this form, the selection takes place subsequently to the marking and through a plurality of selection stages depending upon the complete number marked and not, as before, stage-by'stage, with each stage corresponding to one digit of the number.

The very rapid electronic switching systems lend thernselves particularly well to this latter form of marking and selection.

The object of the invention is to provide an electronic marker in which no conventional electromechanical member having movable contacts is employed, but which employs only static members, more especially magnetostatic relays as defined by applicants in the French Patent 1,160,506, for which the application was filed on November 9, 1956, for Magnetostatic Relay, the corresponding United States application having matured as Patent 2,946,896.

According to the invention, some or all of the subscribers are disposed on a matrix comprising horizontal conductors and vertical conductors, there being associ ated with each horizontal conductor, for example, a tens relay and with each vertical conductor a units relay. There is established at each crossing point between a horizontal conductor and a vertical conductor a link comprising a rectifier in series with one winding of the ringing relay, the number of which is that of the coordinates of the crossing point.

A transistor is associated with one of the two tens or units relays, so that when the relay associated with the transistor is energized or is operative, the transistor is non-conductive, the effect of which i to change the polarity to which one end of the winding of the ringing relay was connected and thus to permit the passage of the current through the winding of the said ringing relay, provided that the relay of the other coordinate (units or tens) has pulled up.

When it is desired to establish a communication through one and the same automatic switch between a calling subscriber and a free called subscriber, the current flowing through a winding of the called subscribers relay, as stated, is sufiicient to operate the said relay, but in other cases a strong current is required to operate the said relay. This is the case, for example, in devices for direct connection to the network. Such devices are known, in which the dialling of a conventional digit produces a search fo a free network line and its connection to the calling subscriber. The marking i therefore effected at the subscriber himself. The latter, who is engaged by reason of the fact that he has removed his receiver, thus has flowing through one winding of his ringing relay a current which polarises it in the opposite sense to its operation. It is therefore necessary in this case to cause a stronger current to how through the winding of the calling subscribers ringing relay than in the normal case of the marking of the called subscriber.

This object is achieved by a device provided into association with the invention, which is set in operation only when certain conditions are fulfilled.

According to the invention, the current fed in the normal case of the marking of the called subscriber flows through two equal resistances in series with the winding of the ringing relay to be controlled and with a rectifier. It is therefore sufficient to short-circuit one of the resistances by appropriate means when the strong marking current is required.

According to the invention, these means consist in the association of two transistors with a magnetostatic relay. The latter is operated only if the special conditions of a strong marking current are fulfilled. In this case, the first transistor is rendered non-conductive by the operation of the magnetostatic relay and the second transistor is rendered conductive. If a resistance is connected between the emitter and the collector of the said second transistor, this resistance is substantially shortcircuited when the second transistor is conductive and the marking current increases considerably.

Further features and advantages of the invention will be apparent from the description hereinafter given with reference to the figures of the accompanying drawings which show by way of example constructional forms of a l00-point matrix comprising 10 tens and 10 units.

FIGURE 1 illustrates diagrammatically the general arrangement of the matrix.

FIGURE 2 illustrates diagrammatically the marking matrix according to the invention in the case of a normal marking current.

FIGURE 3 illustrates diagrammatically a special de vice according to the invention, by which the marking current can be increased in some cases.

In FIGURE 1, the matrix is composed of ten horizontal conductors D ,D B D and of ten vertical conductors U ,U U ,U forming crossing points. At each crossing, for example between the bar D and the bar U a connection point is formed by connection of the point A21 of the horizontal conductor to the point B21 of the vertical conductor through a rectifier R and a winding e21 of the ringing relay whose line number corresponds to the number of the connecting point. A horizontal bar D can be brought to a certain polarity through a switching device such as H and a vertical bar can be brought to the opposite polarity through a switching device V and a resistance R The connecting point is established when a current flows between H and V through the connection A B The switching devices E l-I H ,H are associated each with one of the intermediate tens relays of the register and the switching devices V ,V V ,V are associated each with one of the intermediate units relays. When a calling subscriber has dialled a called subscribers number, the intermediate ten and units relays of this called subscriber pull up and a connection, such as that of H V through A B is consequently established.

In FIGURE 2, only the tens conductors D ,D and D and the units conductors U ,U and U are shown. The constitution of the switching devices H1,H2, HO and V ,V V0 Of 1 is shown in this figure.

Connected to each horizontal conductor such as D of the marking matrix according to the invention as illustrated in FIGURE 2 is the output conductor of an intermediate magnetostatic relay for the recording of a first digit, the said relay consisting of a saturable magnetic circuit D1 connected in series with a rectifier rd and a transistor TD the emitter of which is connected to the rectifier rd and the base of which is connected to a voltage source --U the emitter of the transistor TD being connected to a voltage source U through a resistance 2'. Connected to the collector of the transistor TD is a resistance rD the other end M2 of which is connected on the one hand to the point A and on the other hand to a voltage source U through a resistance RD the value of which is high in relation to the value of the resistance rD There are connected to each vertical conductor U of the matrix, at the point N on the one hand a voltage source U through a resistance rU and on the other hand a transistor TMU through its collector, the emitter of the latter transistor being connected to ground, and the base being connected through a resistance rMU to the output conductor at Q of a magnetostatic relay for registering a second digit, the said relay comprising a second transistor TU the collector of which is connected to the point Q and therefrom through resistor rMU to the base of the transistor TMU and the emitter of which is connected to the intermediate units relay Un through a rectifier, the emitter of the transistor TU being connected to a voltage source U through a resistance rUn The base of the said transistor is connected to a voltage source U The collector of the transistor TU connected to the point Q separated from the base of the transistor TMU by the resistance rMU is also connected to a voltage source ill through a resistance r U The resistance rU is of the same order of magnitude as the resistance rD or equal thereto. The terminals E of the relays Dz D2 Dz Un ,Un Un represent the alternating current supply terminals of the magnetostatic relays, the control windings of which have not been shown.

It will be seen that an intermediate tens relay, such as Dz is directly connected to the corresponding tens bar, while the intermediate units relay U11 is connected to the point N only through the transistor TMU The operation of the device hereinbefore described is as follows: when the whole arrangement is inoperative, i.e. when no intermediate tens or units relay is energized, the transistors such as TMU have the point Q of their base at a negative potential, because the resistance r U is at the potential U,,. Since the emitter is grounded, it is positive in relation to the base, and the collector reproduces substantially at the point N the potential of the emitter, that is to say, ground. No current flows through a connection such as A B although the point M is at a negative potential, because the rectifier RdZl is nonconductive. If, for example, the intermediate relay D1 for the ten conductor 2 and relay U11 for the unit conductor 1 are energised and operate, the points T and Q assume a positive potential. The transistor TMU is rendered non-conductive and the point N no longer has its ground potential, and assumes a negative potential -U through the resistance rU Since the resistance RD is high in relation to rD and the resistance rU is of the same order as rD or equal thereto, the current of the collector of the transistor TD flows for the greater part through the resistance rD the rectifier Rd21 the winging e21 and the resistance rU The ringing relay which has current flowing through its winding e21 pulls up: the called subscriber is thus marked.

It is to be noted that if only one of the two intermediate relays is energised no current flows through the winding e21, because if only the tens relay, for example Dz is energised the points M and N are at a positive potential and nothing passes through e21, while if only the intermediate units relay, for example Un is energised the transistor TMU is rendered non-conductive and the circuit consisting of RD and Rd @121 and rU is looped on itself without including any electromotive force. Therefore, no current can flow therethrough.

In FIGURE 2 it is seen that each of the magnetostatic relays connected to a respective horizontal conducting bar is provided with an output circuit means including the resistance rD and resistance RD leading to the connecting link in which the subscribed relay e is located. Similarly, the output circuits of each of the ma gnetostatic relays associated with the respective vertical conducting bars include output means comprising the blocking transistor TMU and the aforementioned resistances in the collector and base circuits thereof.

FIGURE 3 shows exactly the same matrix device as has already been described with reference to FIGURES 1 and 2, the illustrated part of which is confined to a single ten Dz and to a single unit Un, but to which there is connected between the points T and M a device consisting of a transistor TMD associated with each ten, and of two transistors TMA and TMB sharing a common point P, which are the only ones provided in the matrix, the point P common to the collector of TMB and to the base of TMD being multiplied at the homologous points of the bases of the transistors such as TMD corresponding to each other ten conductor. The emitter of the transistor TMD is connected to the point T and the collector of the same transistor TMD is connected to the point M, so that when this transistor conducts, the resistance rD between T and M is substantially short-circuited. Connected to the base P of the transistor TMD are, on the one hand, the resistance RMB whose other end is connected to the negative voltage U,,, and on the other hand the collector of TMB, the emitter of which is grounded. The base of the transistor TMB is connected to a point K through a resistance rMB, the point K also being connected on the one hand to the resistance RMA, whose other end is at the negative voltage U and on the other hand to the collector of the transistor TMA. The transistor TMA associated with the magnetic core AM, with the rectifier Re, with the resistances rM and RMA and with the negative voltages U Ur and U is defined under the name Magneto-Static Relay in the aforesaid US. Patent 2,946,896. It has been seen that the same was the case with the magnetostatic tens and units relays Dz and U12 respectively. This device operates as follows: In the case of a communication between a calling subscriber and a called subscriber, both of which are connected to the same automatic switch, it is merely necessary to mark the called subscriber, that is to say, to cause his ringing relay to pull up. Since the ringing relay of a free called subscriber is inoperative, a simple marking current causes the ringing relay to change to the operative position, and there is therefore no need in this case for the auxiliary device according to FIGURE 3, the object of which is to short-circuit the resistance 1D. The relay AM is set into operation only if the normal marking current is insuflicient to bring to the operative position a ringing relay which is already polarised in a certain sense. If the relay AM is not energised, the collector of the transistor TMA is nonconductive and consequently the point K is at a negative potential of U through the resistance RMA. The transistor TMB conducts and the point P assumes a positive potential. Under these conditions, the transistor TMD is non-conductive and consequently the tens relay Dz conducts or discharges through the resistance ID, as has been seen in FIGURE 2. On the other hand, it the relay AM is energised, the point K is at a positive potential and the transistor TMB is non-conductive. The point P assumes a negative potential and the transistor TMD changes into the operative position. The points T and M are then substantially at the same potential and the resistance rD is short-circuited by the transistor TMD. The normal energising circuit of the winding e of the ringing relay, which was closed through the resistances rD and rU in series, then only has the single resistance rU. The current flowing through the winding e therefore increases considerably. It the resistances rD and rU are equal, the current is substantially doubled. It is therefore capable of bringing a ringing relay into the operative position even if the latter is previously polarised in the opposite sense, which may be the case in systems for direct connection to the network or in certain automatic switches, in which absolute priority is given to a number of lines for which the communication must always be established regardless of the state of the called subscriber.

The relay AM is therefore rendered operative when the calling subscriber makes use of the direct connection to the network, or in such special cases related to the identity of the calling subscriber. The register, which is capable of identifying the calling subscriber, then does or does not render the relay AM operative, depending upon the circumstances.

Transistors of p-n-p-type have been illustrated in the drawings; it is obvious that a similar arrangement would be possible with transistors of n-p-n-type, with which it would be sufficient to adapt the sense of the polarities appropriately.

We claim:

1. An electronic marking device for marking a relay of a subscriber to be called in a telecommunication system, comprising a marking matrix including a plurality of interconnected horizontal bars and vertical bars, means including an intermediate link for connecting each horizontal bar to each vertical bar at each respective connecting point, said intermediate link comprising a rectifier in series with a winding of a respective subscriber relay at the respective connecting point, a magnetostatic registering relay means including an output means connected to each horizontal bar respectively and a second magnetostatic registering relay means including an output means connected to each vertical bar of the matrix, respectively, the output means of each said second magnetostatic relay including a blocking transistor connected between the re spective second magnetostatic relay and the corresponding vertical bar, means for blocking said blocking transistor when the corresponding second magnetostatic relay is inactive and for unblocking said transistor when the magnetostatic relay is energized, each horizontal bar having means including the output means of the respective first-mentioned magnetostatic relay for applying a potential thereto corresponding to the energized condition of the relay, each vertical bar having means including said blocking transistor for applying a potential thereto to cause said intermediate link to become conductive for energizing said subscriber relay only when the magnetostatic relays connected to the respective horizontal and vertical bars leading to said subscriber relay are energized.

2. A marking device according to claim 1, wherein each magnetostatic relay means comprises a transistor having a collector, the collector of the relay transistor associated with each horizontal bar being connected to the corre- 6 spending bar and the collector of each relay transistor associated with each vertical bar being connected to the base of the corresponding blocking transistor through a resistance.

3. A marking device according to claim 1, wherein a first resistance is disposed between a relay and a common point on the corresponding horizontal bar, the common point being also connected, on the one hand, to one end of a second resistance whose value is high in relation to the first resistance and, on the other, to the respective connecting link, and the direction of the rectifier being such that it is not conductive when said common point has the same polarity as the point to which the other end of the second resistance is connected.

4. A marking device according to claim 3, wherein said blocking transistor is connected between at least one of said vertical bars and the respective relay, said blocking transistor having a collector connected to the common point of the respective vertical bar, the common point between the vertical bar and the collector of the blocking transistor connected to the second magnetostatic relay being also connected to one end of a third resistance of equivalent value to said first resistance disposed at the common point of the horizontal bar, and means for energizing one end of said third resistance at the same potential as said other end of the second resistance.

5. A marking device according to claim 4, wherein each second magnetostatic relay means is connected at its output conductor to a point common to the ends of two resistances, one of said two resistances being connected at its other end to the base of the blocking transistor and the other end of the other of said two resistances being at negative potential, the emitter of the said blocking transistor being grounded and the collector thereof being connected to a common point of a corresponding bar such that, when the respective magnetostatic relay means is operative, the blocking transistor is non-conductive and when the magnetostatic relay means is operative the transistor is conductive and produces a change in the potential of the common point of its collector with the corresponding bar.

6. A marking device according to claim 1, wherein each horizontal bar has input means including an input resistance and wherein a device comprising a further magnetostatic relay associated with two transistors is connected to the terminals of the resistance incorporated in the input of a horizontal bar, one of the transistors being individually associated to short-circuit the input resistance, the emitter and the collector of the said one transistor being connected respectively to the ends of the said resistance, the other transistor being the only one in the marking matrix and being directly connected to the said magnetostatic relay, the point of connection between the two transistors being multiplied with all the homologous points of the transistors associated with the input resistances of the corresponding bars, so that when the said magnetostatic relay is operative the input resistance associated with the said bar during marking is short-circuited by the transistor associated with the said resistance which is itself operative.

7. A marking device according to claim 6, wherein said further magnetostatic relay for the marking matrix is connected by the collector of its transistor to the base of one of said two transistors, the latter transistor having its emitter earthed and its collector connected to the base of the other of said two transistors which is individually associated with a bar, the common points between the base and the collector being each connected to a negative polarity through a resistance, so that, when the magnetostatic relay of the marker is rendered operative, the transistor associated therewith is rendered non-conductive, the latter transistor then permitting the transistor associated with the input resistance of a bar to be rendered operative.

8. An electronic marking device according to claim 1, wherein said subscriber relay is identified by a plurality of 4 digits and wherein the magnetostatic registering relay means connected to each horizontal bar of the matrix is operatively connected for registering a first digit for identifying the subscriber relay and the magnetostatic relay means connected to the vertical bar of the matrix is op- 5 eratively connected for registering a second digit for identifying said subscriber relay.

References Cited in the file of this patent UNITED STATES PATENTS 2,787,666 Flood Apr. 2, 1957 2,857,470 Faulkner Oct. 21, 1958 2,862,060 Ducamp et al Nov. 25, 1958 

